Self-calibration system and method for articulated arm type coordinate measuring machine

Abstract

The invention relates to a self-calibration system and a method for articulated arm type coordinate measuring machine and belongs to the self-calibration field. The self-calibration system comprises a self-calibration device, an articulated arm type coordinate measuring machine, a computer, a self-calibration device cable and an articulated arm type coordinate measuring machine cable, the computer comprises a data collecting card; the self-calibration device is connected to the computer through the self-calibration device cable, the articulated arm type coordinate measuring machine is connected to the computer through the articulated arm type coordinate measuring machine cable; the data collecting card is controlled by the computer for collecting the effective length of the self-calibration device and the corner of the articulated arm type coordinate measuring machine; the effective length of the self-calibration device is the distance between the centre of sphere of the standard ball and the centre of sphere of the ball head of the steel ball. The self-calibration system and the method for articulated arm type coordinate measuring machine can offer data support with stronger robustness for resolving the structure parameter, the resolving reliability and the precision of the structure parameter are improved; the calibration operation is more flexible and light.

Description

technical field [0001] The invention relates to a self-calibration system and method of an articulated arm type coordinate measuring machine, belonging to the field of self-calibration. Background technique [0002] The articulated arm coordinate measuring machine is a multi-degree-of-freedom coordinate measuring device, which is now mostly used in industrial field measurement, product reverse design and other fields. The articulated arm coordinate measuring machine adopts a space open-chain structure similar to the joint robot. This structure makes the articulated arm coordinate measuring machine have the characteristics of small size, large measurement range, and flexibility and lightness. However, this structure has the problem of error accumulation and amplification. The disadvantage is that the structural parameter errors of the joints at all levels will be amplified step by step, resulting in a decrease in the accuracy of the measuring machine. [0003] Kinematics cal...

AI Technical Summary

Problems solved by technology

The articulated arm coordinate measuring machine adopts a space open-chain structure similar to the joint robot. This structure makes the articulated arm coordinate measuring machine have the characteristics of small size, large measurement range, and flexibility and lightness. However, this structure has the problem of error accumulation and amplification. The disadvantage is that the structural parameter errors of the joints at all levels will be enlarged step by step, resulting in a decrease in the accuracy of the measuring machine

[0003] Kinematics calibration is an effective method to eliminate the structural parameter error of the articulated arm coordinate measuring machine, but due to the huge difference in the structure form, the traditional calibration method of the orthogonal coordinate measuring machine cannot be directly applied to the articulated arm coordinate measuring machine, and the robot field The calibration method generally requires the use of expensive precision measuring instruments such as laser tracker and laser interferometer, and the calibration operation steps are cumbersome and the calibration time is long, so the application cost is very high

At present, there are many researches on the single-point calibration method. Due to the limited movement space of the articulated arm coordinate measuring machine and insufficient movement of some joints, the similarity of the collected data is high, and it is easy to fall into local problems when calculating the structural parameters. The minimum solution, the accuracy of the obtained structural parameters is low, so the accuracy of the articulated arm coordinate measuring machine cannot be effectively improved

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